<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        #d1{
            width: 200px;
            height: 50px;
            background-color: #0AA1ED;
            position: absolute;
            /*控制元素的显示层级,值越大显示越靠前*/
            z-index:1;
        }
        #d2{
            width: 50px;
            height: 200px;
            position: absolute;
            background-color: #FF0000;
            z-index:2;
        }
        #d3{
            width: 200px;
            height: 200px;
            /*设置超出的部分是否显示 hidden隐藏 scroll滚动显示*/
            overflow: scroll;
        }
    </style>
</head>
<body>
<div id="d1"></div>
<div id="d2"></div>
<div id="d3">
    <img src="../m2.jpg">
</div>
</body>
</html>